The topic of this talk is the study of extragalactic extended sources with the Sunyaev
Zeldovich effect (SZE). In this respect, I will speak first of the theory of the SZE.
Then, I will discuss three particular cases: the thermal SZE in galaxy clusters, the
non-thermal SZE in galaxy clusters, and the non-thermal SZE in radiogalaxies lobes.
At last, I will discuss the properties that suitable instruments should have to
perform useful observations of the SZE, with a brief reference to a possible future instrument
called Millimetron.
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Most Globular Clusters show star-to-star spreads in the abundances of light elements
resulting from CNO cycling and other proton capture reactions, spreads that are not present in
the halo stars of the same metallicity. A popular model to reproduce these “chemical
anomalies" relies on the ejecta of super-AGB and massive AGB stars evolving during the
first epoch of the cluster life, following the SN II epoch. These models, however, predict
a direct Na-O correlation in the ejecta, so that the anti correlation Na-O, and other
chemical features of the second generation stars, require that dilution with some “pristine" matter.
I explore the possibility that the “pristine" matter is matter of the first generation stars, lost by
gravitational interaction within the cluster core.
This interaction can be a dominant mechanism, provided that the first generation stars
form in a very compact cluster core, as the matter lost by the AGBs accumulates in a cooling flow.
I study the abundances resulting in the matter forming the second generation stars
thanks to this process, and the requirements on the frequency and extent of the mass loss
events that can make this process compatible with the observed Na-O anticorrelations.